UIScrollView

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    //1.滚动视图的使用
    //读取图片内容，显示到图片视图上
    NSString *path = [[NSBundle mainBundle] pathForResource:@"3" ofType:@"png"];
    UIImage *image = [UIImage imageWithContentsOfFile:path];

    //图片视图
    UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, image.size.width, image.size.height)];
    imageView.image = image;

    //滚动视图是在视图大小超过它的高度时使用
    UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(50, 80, 300, 300)];

    //设置背景颜色
    scrollView.backgroundColor = [UIColor redColor];

    //将图片放到滚动视图上面
    [scrollView addSubview:imageView];
    //添加到父视图
    [self.view addSubview:scrollView];

    //设置滚动的范围
    //滚动视图在横向和纵向显示的最大值
    scrollView.contentSize = CGSizeMake(image.size.width, image.size.height);

    //设置横向滚动条的显示
    scrollView.showsHorizontalScrollIndicator = NO;
    //设置纵向滚动条的显示
    scrollView.showsVerticalScrollIndicator = NO;

    //设置回弹效果
    scrollView.bounces = NO;

    //设置偏移量
    scrollView.contentOffset = CGPointMake(0, 0);

    //设置放到和缩小的倍数
    //放到倍数
    scrollView.maximumZoomScale = 2;
    //设置缩小的倍数
    scrollView.minimumZoomScale = 0.5;

    //代理属性
    scrollView.delegate = self;

    //分页显示
    scrollView.pagingEnabled = YES;
    
}

pragma mark - UIScrollView代理

//返回滚动视图中可以放大或缩小的视图对象
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
    return [scrollView.subviews lastObject];
}

//开始滑动时调用
-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
    NSLog(@"%s",__func__);
}

//将要结束滑动时调用
-(void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset
{
    NSLog(@"%s",__func__);
}

//已经结束滑动时调用
-(void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
    NSLog(@"%s",__func__);
}

//在滚动的时候调用
-(void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    NSLog(@"%s",__func__);
}

//减速停止时调用这个方法
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
    NSLog(@"%s",__func__);
}